The invention relates generally to a racket for playing a game with a ball of limited resiliency, especially a tennis racket.
A conventional racket for playing such a ball game comprises a stringing frame portion or racket head, with suitable stringing therein. Adjoining the racket head frame portion is a throat region, which in turn is connected to a handle at the end of the racket remote from the racket head frame portion, by a suitable shaft arrangement. In a conventional tennis racket of that kind, the height of the handle without any cladding or wrapping material thereon, is from 23 to 32 mm while the height of the racket head frame portion is less than the thickness of the handle. The height of the handle and the height of the racket head frame portion are measured in the direction in which a ball is struck by the racket, being therefore measured in a direction which is normal to the plane in which the stringing of the racket lies. A racket of the conventional dimensions referred to above is disclosed for example in German laid-open application (DE-OS) No 30 18 354.
Experiments have shown, that in tennis rackets of the above-indicated kind, when gripped in the region of the handle thereof, the fundamental natural frequency or inherent frequency or oscillation frequency of the racket is 25 to a maximum of 50 Hz; unstringed tennis rackets generally have slightly higher values.
When a ball strikes against or is hit by the stringing, it is known that the ball forces the racket head frame portion out of the longitudinal axis of the racket and results in the reliability of aim of the ball being adversely affected, the above-mentioned deflection of the racket head frame portion also being responsible for the direction in which the ball flies.
Due to the different values of the natural or oscillation of the tennis racket on the one hand and the "ball resonance" of about 125 Hz on the other hand, it can be shown that deviations of up to a meter from the desired line of flight of the ball occur over the entire length of for example a tennis court. The ball-striking accuracy of such known tennis rackets therefore leaves much to be desired.